Pasting of paper, polymer, fabric wallpaper.
Application of liquid wallpaper

Pasting of surfaces by paper wall-paper

Work on pasting of walls and ceilings consists of several stages. Preparation of materials includes the trimming of wallpaper, color uniformity and definition of drawing rolls, cutting of the cloth, they are leveling.
Before pasting all the rolls need to carefully review and pick up on tone. Solid rolls kits for pasting one or several walls of the parlor. Wallpapers with differences in shade can be used for papering the walls with windows that are, or are in other lighting conditions, or partially closing curtains and blinds, but similar to other places with poor lighting or indoor rugs, wall-sections. Defective pieces of wallpaper may be needed for pasting of walls under window openings, with the batteries.

When cutting the roll should fit the pattern of one piece to the picture of a cloth and cut to size. Their length should be equal to the sky walls of the eaves bottom of a frieze up to the plinth with a margin of 100 mm at the wallpaper from the petty figure also up to 250 mm with a wallpaper with a large figure, as if in the latter case by fitting the pattern can be more waste. This margin will allow to eliminate the potential difference similar to the height of places in different parts of the wall due to the uneven floor or ceiling horizontality.

Excess later cut stickers on the baseboard, but the top of the cover border or frieze.
In some cases, paper wall are the side edges of the width of 1-1.5 cm. Thick wallpaper, which are glued back to back, the edge should be cut off with a pair of sides, which will cover the seam, and, in wallpaper, designed for sticking on the right side of the window, cut edge on the right side in the other - to the left.

Cut edges precisely on the designated line. The most convenient way to act is sitting on a chair. Putting a roll on his knees, cut edge, reeling in a roll of wallpaper again. When cut the left edge, the roll is rewound to make it easier to work.

The required length of the cloth is cut along a line drawn by a pencil in advance with the help of the polygon. Cutting the cloth, you must follow the registration patterns, while taking into account that the percentage of material below when cutting inevitably will go to waste. The remaining short pieces of wallpaper store. They are useful for gluing small surfaces under and over the windows, above the door, and for subsequent repair wallpaper.
Apply a vertical line at gluing the cloth first for all subsequent cloth had been glued vertically, which is very proud to save the picture. Apply this line not only in mozhnonikak room corners, but also in other places of the wall.

The first vertical bar is applied at a distance from the angle equal to the width of the cloth with the setting it on the next wall at 10-15 cm. Slugger this plumb line with a cord, rubbed chalk.

Layering the walls lies in the fact that the upper line spacing, but is similar also at the corners for skirting wall panels durable bonding composition coat with adhesive strip 10 cm.

For application of the adhesive composition prepared by the cloth are stacked (up to 10 layers) face down, pushing them against a friend to his friend so that trimmed side of each of the underlying cloth performed at 15-20 mm. In this case, the upper cloth paste promazyvanii not zatechet under the edge of the underlying.
Glue is applied by brush (centrifugal, or maklovitsej fleytsem) along the length of the cloth, evenly distributing it on the surface. Please spend a strip in the middle, then lubricate the remote side of the cloth as well as, finally, the outskirts, which is closer to the operator. Make sure that the glue does not got to the front side and that does not have gaps. The edges of wallpaper must be lubricated with particular care, otherwise they will be left behind in the joints. .

Thin wallpaper plaster once with cold glue (paste), thick - a couple of times warm. Panels of dense wall-paper, smeared with glue, soak the beginning, becoming wavy and curl up at the edges. This indicates that they are not ready for bonding to the surface. Hang mozhnotolko while, at what time will the cloth wholly smooth.

Thin wallpaper coat with centrifugal brush at once liquid glue, distributing it evenly layer from the middle to the edges and removing clots and other tiny foreign particles. Pasting them again after promazyvaniya glue.
Wallpapering should be venturing away from the window, advancing into the room: in this case the edges of panels, glued lap, do not cast a shadow and become less noticeable.

When one individual is working, come this way. Take a cloth smeared with both hands. First, an impressive forefinger and folded it in two-thirds also pick up the rest of the fingers on the front side of the folded portion. The cloth is also transferred to the raised wall. On the marked lines is applied to the top edge of the top features of the spacing, line the margin (the first panel paste features on plumb - vertically). Only later, as if the upper side of the established right under the ceiling, and the entire band will be located vertically, it is smoothed large soft brush or a clean cloth on top first, but then in the middle. In this state, the band still mozhnosdvigat and send its location. Then folded and glued bottom. If the floor has a plinth, the wallpaper is inserted carefully with a knife or a chisel in the junction between the skirting and the wall, but the remainder of the lower edge of the strip is cut and paste a strip on top, overlapping the seam and the upper part of the plinth. If the baseboard is removed easily, it is removed, the wallpaper is glued to the floor, but then again, nail the baseboard. Then, the entire surface of the cloth smooth brush, but roller joints, making sure that it is well glued over the entire surface. When bringing up their blistering cut blade as it smoothes the room. Minor bubbles on the surface will not be smooth - after drying of wallpaper, they will disappear.

If the wallpaper glue close to the ceiling, the edge of a panel adjacent to the ceiling, tuck about 5 cm to the glue not to stain the ceiling. The cloth is tightly pressed to the wall at the top and after checking its vertical movements of the brush down smooth. Pencil mark as you need to cut from the strip at the top if it was tucked at the ceiling. Just stick the rest of the web.

Gluing together is more convenient, especially when paste wallpaper with a pattern that needs to be customized. One lubricates cloth glue, folds it takes two hands and submits to another (so as not to stain the wallpaper in the transmission partner, should be lying cloth grab one end of the corner of the impressive and index fingers of both hands, lift and bend toward the left to lie on the floor of the cloth about a third of the total length. Middle fingers pick up the banner below to span another third also raise the floor, letting it hang on the middle finger. In this arrangement, the panel would be folded three times, and smeared with glue elements will be converted to one another), standing on a stepladder or scaffolding (the table), which beret for one end of the web, dissolves it also applies to the wall, starting at the top end of the top edge to the line spacing, but located at the bottom evenly pulls the fabric at the bottom and the side part applies to the vertical line. The next panel is glued, adjusting the image to the previous wallpaper.

Wallpaper light colors need to smooth out by placing a brush or rag paper. If the edge of the cloth acts as glue, it must be immediately removed with a damp sponge foam. Hold the brush on the glue, stepped out of the joints, is not recommended, as it can stain or damage the front surface of the wallpaper. Random spot of adhesive on the surface of the wallpaper is similar should immediately remove with a sponge.

Paper wallpaper paste with an overlap of the edges in the course of the window so that the top margin of wallpaper lying exactly along a broken line above, but trimmed edge overlaps the edge of the previous uncut cloth. Very proud at the same time monitor the registration pattern. If for some reason the image does not fit together, the cloth can be pulled down over the previous alignment until filled. Upon reaching down to the room corner panel should last try and cut lengthways so that it overlaps the seat at an angle of 3-4 cm. To wallpaper does not appear folds of cloth part overlapping angle before bonding an incision in a few places. The following panel pasted on the angle, focusing on the features of the upper and vertical spacing.

In the process of work, particular attention should be paid to ensure that the joints of panels were well adhered. If they later drying depart from the base, glue them will be very difficult without appreciable defects.

Switches and sockets with a sticker wallpaper can also did not break, turn off voltage is sufficient (unscrew the plug or switch off the circuit breakers) and remove the cover. The canvas, not smeared with glue, combined with a pattern previously pasted paintings, noted on it socket or switch the focus position are also cross-shaped incision is made through the center. The incision will allow qualitatively to paste banner. Places around the sockets and switches carefully smooth. After drying wallpaper incised margin carefully cut a razor blade along the contour of the socket or switch box, fasten the lid and include voltage.

If the walls, Wallpapers, pass the pipe, or their color to match the base color of wallpaper or Wallpapers. Pre pipe paint to protect against corrosion. Then the paste over two layers of paper so that its edges glued to the wall of the pipe on both sides of the width of 15-20 mm. Dry cloth wallpaper is applied to the previously glued to align the figure, are cut from the strip and paste over his pipe.

After gluing and drying wallpaper in excess of their cornices and moldings are also begin to cut the label border. Border covers uneven upper edges of wallpaper. If you have previously beaten off horizontal line (line spacing), glued wallpaper, apply a new one with a ruler and a pencil and glue the pieces on it curbs up to two meters. To curb is better to keep, you can miss the mark until the stickers paste the entire "track", to which he will adhere, allow to dry for about 30 minutes and to start the label exactly on the planned line.

Dries wallpaper should slow, so the location can not be papered arrange drafts, heat it using electrical appliances.

After pasting the walls should be allowed to dry at least a day would also only then you can arrange the furniture in its place.
Hole or tattered room on the wallpaper can be repaired patch. Take a piece of the size of the room some more close up and very carefully customize drawing. At the edges of the patch are jagged incisions. Jagged edges better blend in with the general background wallpaper, and when the glue is dry, it will be about invisible.

The damaged portion mozhnozamenit insert. Do this as follows. Take flap such as wallpaper, it is cut dimensions exceeding the dimensions of the insert is applied to the damaged area, carefully aligning the drawing, as well as securing the adhesive tape around the edges, with a sharp knife or razor cut insert. Thereafter, the damaged portion is removed and the glued insert.

In recent years, practiced as papering ceilings. To this end, as if the situation used white glossy or matte wallpaper. Sometimes in an impressive room ceiling wallpaper paste over the same, which is also the walls. Panels glued parallel rays of light from the window to the joints were less noticeable.

In preparing the ceiling under pasting perform the same operation in the same sequence as well as pasting the walls. However, the paste has to be more dense as insufficiently viscous glue is not able to keep the wet wallpaper on the ceiling.
Pasting of ceilings is best done three. Smeared glue cloth is folded accordion also served a pair of runs at the top of that, spreading it pressed in different parts of the surface and smooth. Glued wallpaper on the ceiling must be exactly the room as quickly, or they may come off.

If the wallpaper on the ceiling has to be glued to one, they are folded like an accordion, a rigid roller support (eg cardboard) and alternately pressed against the ceiling areas, limited folds. Thus one hand smooth cloth and retain the remainder of the other, folded in concertina.

When in place as tall walls 2.5-3 m, the first paste over ceilings. Panels with cut 50-100 mm longer and give birth to them on the wall. When pasting the walls of the data sections glued wallpaper.

In areas of more than 3 m tall as often with leaves frieze Wallcovering 200-300 mm. In this case, the wallpaper on the ceiling and paste to transfer to the wall, this stock has to be 500-700 mm, respectively. Then on a wall beat off the top of the horizontal line so that the cloth wallpaper wallpaper wall blocked frieze.

Pasting wallpaper light requires great accuracy and thoroughness. Hands should be all the time to clean.

Defects when wallpapering their elimination

Full or partial peeling wallpaper frieze around, curbs or on top of the walls. Wallcovering made on the surface previously painted by glutinous or limy paints, wallpaper urgent drying due to drafts or excessive heat, the use of liquid adhesive with dense wallpaper. When adjusting bend peeled off part of the wallpaper glue Nabeul shade on the surface fluff wallpaper glue, stand up to the swelling and then pokleit. When pasting ought to evade drafts and use the adhesive in accordance with the density of wallpaper.

Peeling wallpaper in casings and baseboards. Wallpapers and gluing facilities were badly missed the mark with glue. When adjusting wallpaper bent, thoroughly coat with the adhesive surface in the skirting boards and architraves, promazyvayut wallpaper, give them swell and then pasted, smoothing fine.

Bubbles also folds formed by the slow drying of the low temperature, the use of strong glue wallpaper with thin, smooth sloppy, wallpaper insufficiently sustained after smearing glue and does not swell. Wallpapers perekleit taking measurements to increase the temperature in the place of insufficient ventilation and removing cause. If you used a strong glue to replace him in accordance with the density of wallpaper. It's important to smooth the wallpaper, keeping them lubricated for swelling necessary time.

Wallpaper in the corners of the walls are broken. Paper wallpaper glue when namazyvanii expanding, but at a greatly reduced drying. The angle was blocked by solid web. Wallpaper-stick so that the angle of the edge of the wallpaper overlaps the width of 3-4 cm. Thick seams. When the label of the new wallpaper seams coincided with seams of old wallpaper, which can not be cleaned off or thick wallpaper glued lap. Perekleit wallpaper stripping previously pasted, wallpaper pasting tight butt. Fabrics Wallpaper positioned crookedly. Sticker performed without punching vertical line using a plumb line. Correcting is possible only by plywood.

The edges of wallpaper covered with paste, which also tread through the wallpaper. Sticker performed hot paste, penetrated the front of the wallpaper through the thin paper. Correcting route plywood with cold or hot glue with the temperature not exceeding 30 ° C.

Visible seams. Pasting lap in front of the light. Correcting route plywood, gluing venturing from the window opening.

From under the new wallpaper view old. In the manufacture of wallpaper applied aniline dyes instead of pigments. Change the wallpaper.

Having solid blotches under the wallpaper. Pollution of surface paste or solid particles. Perekleit wallpaper, strain glue or stripping the surface.

Pasting roll and film materials
polymers based on

The sequence for the polymeric film pasting operations and rolled materials is about the same as well as in paper wallpaper decoration, but there are also the features.

Polymeric materials unpack and unwrap mozhnopri temperature not below + 15 ° C. If the materials are kept at a low temperature, they should be kept in the previously warm area of ​​about 24 to 48 hours.

Panels raskraivajut, leaving a margin for adaptation to skirting boards and other components.

When pasting films on paper or fabric-based wall Makhov brushes glue is applied with a thin even layer on all surfaces. Stack is placed on the table of 5-6 panels face down, brush or maklovitsej glue is applied as it is shaded around the cloth.

Smeared cloth folded buttered side inside and hang on specially prepared crossbeam, where it must be kept for 5 to 10 minutes.

Films on a paper basis paste as a butt, so as to fit lap relief pattern. Seams carefully smooth with a damp cloth. Excess adhesive is removed with a damp sponge or cloth. paper-based films need to start over baseboards and trim, but not cut.

Films cloth as baseless and glued to the wall first lap with overlap of 10-20 mm, followed by smoothing of seams elastic rubber or plastic spatula from the center to the edges of panels and from top to bottom. Glued cloth incubated 3-4 hours, but the seam is then cut with a sharp knife or a razor in the holder. Slaughtered edges coat with glue, connect end to end and smooth down. After finishing work with a stiff brush and warm soapy water is removed from the adhesive spot welds on the panel. Bubbles also eliminate bloating piercing needle or razor blade IDC also smoothing.

Self-adhesive film is glued as follows. With the prepared cloth remove the protective paper on a site of 8-10 cm, and the adhesive surface is fixed on the top line spacing. Thereafter, the cloth is removed from the backing paper over the entire length, tear off the wall and secured share shall be verified by a vertical line. The upper end of the cloth is applied over the top of the line spacing is also pressed against the wall from top to bottom and from the center to the edges with a soft brush. should peel and squeeze again in the case of education of bubbles or wrinkles in the film room. Definitively pasted film is smoothed with a clean cloth. The following panel pasted overlapped with an overlap of different cloth 5-10 mm. Edges should be turned towards the window that the seam did not give shadows.
Linkrus pre-soaked in water for at least 6 hours (soak mozhnonakanune evening). Then with a sharp knife along the long edge of the rail clip. Pruning should be done very carefully so that when pasting between bunting does not have gaps. Fabrics are stacked face down, and smeared flat handbrake or centrifugal brush glue (it should be viscous and solid, otherwise not be able to keep linkrust on the wall dries). Wall coat with glue. Smeared with glue fabric is one of the workers, standing on the scaffold (the table), takes over the top edge of, and the second - for the bottom. The cloth is applied to the wall on top of the features of the beat and the vertical line is also smooth. The following other cloth glued butt so that was not noticeable joints well-matched pattern.

At the top of the wall elements are often linkrust trim wooden slats, varnished.
Linkrust dries through 7-10 days, other times it later this stained by oil or enamel paints.
When finishing vinistenom just before gluing the cloth adhesive applied to its back side with a notched trowel layer 1-1.2 mm. The cloth is pressed against the wall by the vertical line spacing or lines the top and carefully smooth. Clay could not hold back the cloth again after application, so you need to temporarily fix the sheet at the top elements of wooden slats and thin nails, on one third hammered into plaster. In a day nails and bar mozhnosnyat. Vinisten difficult to glue in the corners. So it's best adjacent to the corner of the cloth cut out in such a way that its edge repeated a corner. Thus raskraivajut also include cloth, pasted on another wall. If the joints are visible, their mozhnoprikryt reechkami wood, lacquered.

Foam as well as also vinisten, glued back to back. Adhesives on the back of Foam should be applied thickly. In connection with considerable thickness and embossed surface Foam difficult to stick in the corners. That he did not depart, in a place of his inflection mozhnona several days to press a wooden rack.

Switches and sockets before gluing of all film and roll materials should be removed by disconnecting the voltage, but after gluing cut out the necessary opening and set them in their place.

pasting cloth

Special charm, comfort room attached to the walls, floors, pasted over with a cloth. For finishing used linen and cotton fabrics, burlap. Attach the fabric to the wall as possible, in addition to gluing, similar as by rails or frames.

When sticking fabric surface of the walls is necessary to prepare as if under pasting by self-adhesive films: it must be absolutely smooth, well proshpatlevannoy. Hang the fabric on the walls is best to glue on the basis of CMC, mastics "Bustilat" and "Gumilaks" casein glue, but similar to flour paste.

Due to the fact that when wet tissue and drying shrinkage can provide a strong, it must first check on a separate piece. For this piece of cloth should be wet and dry. If it turns out that the fabric strongly sits down, it must be all wet and dry (this process is called dekotirovaniem). When a small shrinkage mozhnoispolzovat fabric without soaking: a small shrinkage will contribute favorites stringing it to the surface.
First, cover the wall with a thin layer of glue, then placing the fabric butt and smooth it with a brush. Smoothing produces "herringbone" - top from the middle to the edges of the web, all the time to controlling the junction with the adjacent blade.
As is known, on walls, cloth-covered, going to a lot of dust particle, so they need to be cleaned out regularly with a vacuum cleaner. Therefore it is better again later stickers and dry cloth to cover a thin polymer film. In this case the fabric are much longer. For polymeric film coating sprayed fabric perchlorvinyl its solution in acetone resin (50-75 g of resin in 1 liter of acetone) or with varnish.

Prepare a solution in a glass or enamel pot, stirring with a spatula or a wooden stick. The solution was applied with a sprayer.

For pasting sexes used a thick cloth, and floors must be very smooth and smooth. To do this, zashpatlevat floors in all the cracks. For this purpose, the putty, which is made at home. Take a speck of dust or wood shavings melkoproseyannye added to nitrocellulose lacquer, dispersion of PVA or liquid glass (silicate glue office) and knead until the consistency of liquid sour cream. Then the mixture sealed seams or gaps in the floor. After drying, stopper premises sanded sanded, first, medium-grained, then fine.

If Shpatlevanie did not manage to get a flat surface on the floor mozhnonastelit sheets of solid wood-fiber boards, carefully matching the edges.

Fabric mozhnonastilat directly on the linoleum or chipboard. Before nastilkoj should remove the baseboards, then spread out the cut fabric pieces on the floor and each carefully stretch, smooth and nail small nails, paying particular attention to fit the pattern. Then cover the nail tissue. special parquet lacquer (without the acid curing agent) may be used. The varnish is applied using foam roller in three layers, each of which has to dry completely. After that, nail baseboards, they are also similar to stained varnish.

Paul is very beautiful, there is no need to lay carpet on it. Gender is not electrified.

Pasting of doors

Door trim fabric and similar mozhnootdelat film and roll materials. You can use ordinary paper and wallpaper, which are covered with walls of rooms, but it is better suited for this purpose as baseless, self-adhesive film, the film on a fabric or paper-based and vinisten. They are less polluted and more resistant to damage. In recent years, it is time very popular for pasting the door in the hallways, bathroom, toilet and kitchen use Foam. But as soon as practicable for the hall and corridors.

For pasting the door leaf must be removed from its hinges, remove the handle and latch kljucheviny also put on two stools. Surface sanded sanded, carefully remove the speck of dust with a damp sponge, primed and paste over compositions in sequence, described above for the corresponding foil and roll materials. Unbonded adhesive film, cut to size, before applying you must roll to roll and deploy them in the process of gluing, rolling on track. First, you need to separate the backing paper and attach it to one of the edges of the cloth, roll and roll, gradually separating the protective paper and smoothing out the film with a soft brush or cloth.

BTonkie Film materials should stick with calling for the edge of the door leaf, but later glue dries carefully cut with a sharp knife or razor blade around the perimeter.

BKogda edge of the door leaf zaovaleny difficult level. the film cut around the perimeter in certain areas it can not stick. In such cases, the contour of the door leaf in the interval of 20-30 mm from the edge of the groove are also wide depth of 4 to 6 mm. The film is cut in advance according to the width equal to the spacing between the outer edges of the grooves. After bonding film utaplivajut edge into the groove, which then stick to the glue polyvinyl chloride or nylon harness. For this purpose, use a plastic mozhnotakzhe furniture or wooden batten reechku. In this case it is necessary to provide a groove of appropriate dimensions.

BPri pasting vinyl leather, vinistenom penoplenom or ends of significant thickness of door leaf mozhnoprikryvat wooden plates, bars or U-shaped plates. To this end, fabric must be cut down as sostrogat a plane around the perimeter on the lining or layout width.
When pasting casings particularly difficult cutting material is subject fit his figure, but similar zaovalennymi shaped casings.

Application of liquid wallpaper

Technology application of liquid wallpaper is simple and accessible to everyone.

The most important step for the quality of application of liquid wallpaper is the preparation of the treated surface. It should be the complete removal of old wallpaper, glue stains and so on. N. Liquid wallpaper mozhnonanosit on plastered walls, walls, painted with oil or water-dispersion paint. Metal items must be primed enamel or oil paint, plastic and plastikovidnye surface -Water-dispersion paint with addition of PVA glue in the container for 10-15% of its amount. If the existing coating has an intense color, in order to avoid its manifestation outside through applied composition liquid wallpaper must be used as a primer composition waterproof (special primer, oil paint, enamel and so on. P.) And priming carried out in vapor layer.

In the next step (after the primer drying) the starting material - dry composition - thoroughly mixed in a plastic vessel filled with water, gradually added in portions until a smooth viscous consistency of sour cream. When the solution removed from this large inclusions material. To speed up the preparation of liquid wallpaper used warm water with the temperature near 25 ° C. Thereafter, the batch is held for 15-20 minutes and before applying again mixed. For a perfect homogeneity of color coating solution at the same time it makes the preparation of several packages. For customizing the interior of various decorative additives are added to the mishmash of liquid wallpaper. All prepared for the work surface should be covered in one step. Therefore it is necessary to prepare the necessary number of material in advance.

Application of liquid wallpaper is performed using pnevmoraspylitelnogo gun or by hand - with a plastic trowel or paint roller with a hard coat.

When spray gun must use a compressor with a working pressure of 0.4-0.5 MPa and a capacity of at least 400 l / min, gun nozzle section - 5.7, 10 mm depending on the texture of the coating type. The optimum flow of spray is achieved by changing the water tank to be deposited in the material. Productivity is 25-45 m2 / hour.

In the event of a gun is first applied to a small layer covering the wall vsploshnuyu. After it has dried, a final coating with the required density. If conventional spray coated in one step, then at normal density coverage in some parts of the walls may creep coating during spraying.

In the case of applying the composition of the solution is made by hand in small portions to throwing by a wall and leveling his paint roller with a hard coat or smoothing voluntary movements using a plastic trowel. The textured finish is performed using embossed rollers. Wrapping pattern is made through 4-8 hours after application to the surface of the liquid obsev. In the process of drawing roll moistened with water regularly.

Versatility of the material can, in some cases, to do without plastering. Masonry, wall tiles, plasterboard, particleboard and other surfaces are covered in a couple of stages. First, liquid wallpaper shpatljujut seams. Then, after they have dried, apply a second decorative layer.
Do not leave an unfinished surface. Suspension of work should be completed up to the setting of the material.

Do not apply liquid wallpaper in the rooms where the temperature is below 10 ° C.

Damage layer takes its final form as the paint after drying. For quickest drying liquid wallpaper is desirable to provide good conditions at the site of ventilation (as opposed to conventional wallpaper drying process). The drying time of coatings in a well-ventilated room with a temperature of about 20 ° C - 1 to 3 days.
Depending on the condition of surface to be coated with one kilogram of dry mix can be covered up to 2-3 m2 surface.

Longevity cover 10 years.

In carrying out the repair work of the damaged or contaminated wall coverings moistened with water, it is removed and then overwritten again prepared mixture. At cosmetic repair coating is sufficient to refresh the water-dispersion paint with every coloring filler.
If the surface you are tired or you have changed something in the environment and you can not fit the color or texture, failures moistened, gently remove with a spatula, soaked in water and then applied to the other surface.